Left ventricular torsion based on 2D speckle tracking echocardiography (STE) is preload insensitive

Abstract

Left ventricular (LV) torsion plays an important role in myocardial performance. 2D special tracking echocardiography (STE) has emerged as a promising tool for LV torsion analysis. It is unknown if LV torsion is affected by alterations in preload. We sought to determine whether acute preload reduction by Lower Body Negative Pressure (LBNP) affects 2D STE derived LV torsion parameters. LV apical and basal rotation and peak early diastolic torsional rate were measured by 2D STE in 12 healthy subjects (26±1 yrs, 6 females) before and during LBNP to −10, −20, −30, −40 and −50 mmHg levels. LV total torsion was calculated as the net difference between systolic apical counterclockwise rotation and basal clockwise rotation. Peak early diastolic torsional rate was also measured. Compared to baseline, LBNP caused significant decreases in LV end‐diastolic volume (P<0.05) and stroke volume (P<0.01) while heart rate increased (P<0.01). Interestingly, multiple indices of LV torsion including LV total torsion, apical and basal rotation and peak early diastolic torsional rate, were unaffected by LBNP (all P>0.05). These data support the concept that LV torsion parameters assessed by 2D STE are preload‐independent indices of myocardial function. Quantification of LV torsion by 2D STE may, therefore, provide a relatively load‐independent measure of myocardial performance.Supported by P01 HL096570 (LIS); UL1 RR033184 (LIS).